Multiple switch interlock



Oct. 19, 1948.

R. L. WOLFF ET AL MULTIPLE SWITCH INTERLOCK Filed Aug. 7, 1944 @Imm /5 Robezi L.W0Zff William Weber INVENTORJJ AT TRNE'Y UNITED STATES PATENT OFFICE MULTIPLE SWITCH INTERLOCK Application August 7, 1944, Serial No. 548,330

(Cl. 20D-5) Claims.

This invention relates to improvements in releasable latching means for electric switches and particularly to means for interlocking the several units of a multiple unit switch to permit only one of the switch units to be set in a position other than the initial position at any one time.

Multiple switches are used for example in selecting the frequency bands at which radio transmitters and receivers are to operate, in centralized communication or call systems, in testing equipment of various kinds, in business machine-s, and for various other uses where it is desired to complete any one of a plurality of circuits. However, in all such uses only one of the circuits should be completed at any one time, and means must therefore be provided which will positively return any one of the switches to an initial or given position from any other position upon movement of another switch out of the given position into another position.

It is therefore one of the objects of the present invention to provide a releasable latch for a multiposition electric switch in which the switch is releasably held in a position other than a given position and is automatically returned to the given position upon release of the latching means.

Another object of the invention is to provide a switch for controlling a multiplicity of circuits in which a plurality of switching units are so interrelated as to return any previously operated switch unit to a given position upon movement of any other switch unit out of the given position.

Another object of the invention is to provide a simple and compact multi-unit switch with an interlocking mechanism, which is simple and completely reliable in operation, for causing the return of any previously set switch to a given position upon the movement of any other switch out of the given position.

Multiple switches of the character to which the present invention particularly relates are disclosed, for example, in Patents 2.291516 and 2.291,51?, both issued to R. L. Wolff on July 28, 1942, in which a plurality of identical switch units are mounted on a panel for individual operation to control a plurality of circuits. The individual switches comprise a mounting bracket having a portion supporting a xed or -stator member of the switch and other portions supporting a movable or rotor switch member. The bracket portion and the switch stator supported thereon denne substantially a circular space in which the rotor is so located that its contact elements are engageable with the contact elements of the 2 stator. An operating lever is iixed to the rotor and extends through the base of the bracket and through the panel and is formed with a sectorshaped portion engaging the ends of a spring wrapped about the rotor pivot. The spring is tensioned upon movement of the rotor out of the given or central position to either of two other or side positions by engagement of lugs on the Switch lever with the several ends of the spring. Upon release of the lever by the operator. '1e spring returns the lever to the given or central position.

Objects and advantages other than those above set forth will be apparent from the following description when read in connection with the accompanying drawings, in which:

Fig. 1 is a side elevation of a multiple unit switch with all but two of the switch units rcmoved and embodying the interlock or latch of the present invention;

Fig. 2 is a top plan view of Fig. l to show the relation of the switches with the panel and the interlock plate;

Fig. 3 is a bottom plan View of Fig. l;

Fig. 4 is a sectional view looking downwardly on the plane of the line IV-IV of Fig. 6;

Fig. 5 is a top plan view of the panel only; and

Fig. 6 is a fragmentary sectional View taken on the plane of the line VI-VI of Fig. l.

Referring more particularly to the drawing. the reference numeral Il] designates a on which are to be mounted a multiplicity of identical switch units herein shown as ve in number. The panel is adapted to be mounted on a suitable support, as by bolts or screws passing through. holes Il. and is formed with a plurality of slots I2 therethrough. Spacers i3 in annular form extend from the panel, preferably at the ende of each of the slots, and may be formed from the panel itself or may be formed as short cylinders set into holes in the panel. Each pair ci spacers receives bolts, rivets, or other suitable means, i6 for securing to the panel in spaced relation, one of a plurality of switch units generally comprising a mounting bracket, a stationary or stator member, and a movable or rotor member.

The switch mounting brackets may be with a base portion I1 formed with holes t ro gli which the mounting bolts l@ pass, a Xefl s ch member supporting plate i8 and movable switch member support plate I9 being formed Yfrom the base at right angles and in spaced relation thereto. It will be understood that the bracket il, i2. and i9 may be made integral or in Separate tions suitably secured to each other.

por- The bracket plate I8 is preferably formed with ears extending upwardly from the edge of the plate at the ends and in the center thereof. A fixed or stator switch member 23, formed of insulating material, is substantially U-shaped and the legs of -the U are suitably secured to the end ears on the stator bracket plate I8. The switch stator 23 carries a plurality of xed 'contacts on each side thereof, as indicated at 24 and 25. Such contacts are preferably of double layer or leaf con-struction with the ends of the leaves bent and rounded to provide resilient double wipe contacts for the movable switch member, as is well known. The conductors of the several circuits to be controlled are connected to the ends of the contact clips or members 24, 25, as is also well known in the art.

A movable switch member is provided in the form of a disc or rotor 2B mounted on a pivot 29 which is supported at its ends on the center gear of the stator bracket plate I8 and on the bracket plate I9. The switch rotor 28 is formed of insulating material and has mounted on the sides thereof contact members 38 and 3| selectively engageable with the several contact members in the series of contacts 24 and 25, respectively. The rotor 28 has secured thereto an operating lever including a tang 32 with arcuate wings 33 projecting therefrom. The lever tang 32 extends through the panel slots I2 and is provided with a handle or knob 34 for oscillating the rotor until the tang 32 contacts the ends of the slots I2. The operating lever is provided with holes 31, 38 and 39 of the same shape'and size and having a function to be described hereinafter. The holes 31, 38, and 33 are preferably arranged with the hole 38 on the axis of the lever tang 32 and with the holes 31 and 39 in the lever wings 33 equi-distant from the hole 38. The rotor 28 is biased to a given or central position by a spring 42 coiled around the rotor pivot 29 and having the ends thereof projecting into positions to engage in the ends of a slot in a rotor bracket plate I9 or to be engaged by ears 43 and 44 formed on the lever tang at the base of the wings extending therefrom.

The several switch units are interengaged or interlatched by a plate 45 of less width than the panel I and of such size as to iit thereon in easy sliding contact in a space defined by the panel 18, the spacers I3 and the several switch mountthan the panel slots I2 and each formed with a cam-like projection 41 extending into the slots from a side thereof and substantially on the longitudinal axis of both the panel and the plate. The latch or lock plate 45 is reciprocably movable in the space provided therefor and is biased toward one end position by a spring 48 connecting the plate 45 preferably with one of the switch bracketI plates I9, as shown. Before the spring 43 is attached, the panel slots I2 and the plate slots 36 may be brought into registry so that the cams 41 do not project over the panel slots and do not interfere with the extension of the switch levers therethrough. The force of the spring 48 is so chosen that attachment of the spring moves the latch plate to cause the cams 41 to extend over the panel slots I2 and, in effect, divide such slots into two portions.

In the use of the structure herein described, the switch springs 42 tend to hold the switch rotor 28 in its given or central position and the latch plate spring 48 urges such plate into one end position. In such positions of the switch units and the latch plate, the cams 41 engage the center lever holes 38. When one switch is to be moved to a position other than the given position, that is from the central position to a side position, as is indicated in-Fig. 4, pressure of the switch operating lever 32, 33, 34 causes a camming action on, the projection 41, thereby forcing the latch plate to move on its longitudinal axis as also indicated in Fig. 4. All of the cams 41 are then disengaged from the rotor center holes 38 but the rotor biasing springs 42 hold all of the switch rotors 28 in the center position except for that switch rotor to which pressure is being manually applied. As soon as the hole 38 in the lever of the switch being actuated slips off its cam 41, the spring 48 returns the latch plate 45 to its former position. The cams 41 then reengage the center holes 38 of the switch rotors which are not then being moved, and the cam 41 associated with the switch being moved engages with either the hole 31 or 39 of the lever thereof, the hole 39 being engaged if the rotor movement is in the direction indicated in Fig. 6 to move the switch rotor into the position shown in Fig. 4.

In such position the ends of the switch spring 42 are moved into the position indicated in dotted lines in Fig. 6 to tension the spring. If it is now assumed that another switch rotor is moved out of the central position into eitherl of the side positions, such movement again shifts the plate to move all of the cams 41 out of the switch lever holes then engaged thereby. The hole 39 of the previously set switch rotor is released from its cam and its spring 42 returns the rotor to the central position. It will be seen that any one switch may be set in either of two positions other than a given position and will be retained therein until another switch is moved out of the given position whereuponl the previously set switch will return to the given position. It is accordingly impossible at any one time to set more than one switch in any position other than the given position. The means for releasably latching any one switch in any of a plurality of positions other than a given position comprises a simple plate with slots having a cam projecting thereinto and a spring urging the plate toward a predetermined position at which the cams in eifect divide the panel slots into two sections. It will be noted that the latch plate spring should be chosen to have a force greater than the force of anylever during its action on any cam to insure return of the latch plate to the predetermined position after each movement thereof.

It will be understood that any single switch may be manually moved from the central position to either of two side positions and manually brought back to the central position at any time, and that the latch plate will retain the single switch in either of the side positions until the switch is manually returned t0 the center position or until another switch is operated.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from thespirit of the invention or from the scope of the appended claims.

We claim:

1. In a multiple switch, a panel, a plurality of switches mounted on the panel for movement into any one of a plurality of positions and severally including a lever extending through the panel for moving the switches to any one of their several positions and a spring biasing the movable switch portion into a given position, a plate having cam surfaces engaging each of the operating levers while in any one of said plurality of switch positions for releasably holding one of the switches in a position other than the given position against the action of its springr and releasably holding the other switches in the given position, movement of the plate resulting from movement of any switch out of any of its positions and releasing the previously positioned switch for return by the spring thereof to the given position.

2. In a multiple circuit switch, a panel, a plurality of switch units mounted on the panel and movable into a plurality of positions, the switch units each including a lever extending through the panel and a spring biasing the movable switch portion into a given position, the operating levers having a plurality of holes therein severally corresponding to a plurality of switch positions, a plate with cam surfaces individually acting on the levers and selectively engaging in one of the holes therein when said levers are in any one of said plurality of switch positions, and a spring urging the plate in one direction, movement of any switch position causing movement of the plate to release all of the switches from engagement with the plate cam surfaces.

3. In a switch for controlling a plurality of circuits, a panel having a plurality of spaced slots therethrough, a plurality of switches mounted on the panel and including operating levers extending through the panel slots, a plate mounted adjacent the panel and having slots therein with complementary cam surfaces projecting into each of the slots from a side thereof, and a spring biasing the plate to maintain engagement of the cam surfaces with the levers to thereby hold one of the switches in a position other than an initial position until movement of any one of the switches out of the initial position.

4. In a switch for controlling a plurality of electrical circuits, a panel having a plurality of slotsv therethrough, a plurality of multi-position switches mounted on the panel and including individual operating levers extending through the slots and springs severally urging the switches toward an initial position, a plate mounted on the panel for movement relative thereto and having slots therein with a cam surface projecting into each of the slots from the sides thereof for severally engaging with the levers in any one:

of the selectable positions thereof, and a spring biasing the plate to maintain contact of the cams with the levers whereby one of the switches is held in a position other than the initial position until movement of the plate upon movement of any switch out of any position.

5. In a switch for independently completing one of a plurality of electrical circuits, a panel having a plurality of slots therethrough, a plurality of multi-position switch units mounted on the panel and including operating levers extending through the slots therethrough, the levers having a plurality of holes therein corresponding to switch positions, a plate mounted between the panel and the switches and being movable parallel with the panel, the plate having slots therein with cam surfaces projecting from the slot walls into the slots and severally engageable with one of the lever holes in any one of the selectable positions thereof, and a spring biasing the plate to maintain engagement of one of the cam surfaces of the plate in one of the holes in each of the levers for releasably holding the switch units in a position other than an initial position until l movement of any switch out of any position.

ROBERT L. WOLFF. WILLIAM WEBER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,008,514 Armstrong Nov. 14, 1911 1,105,485 Carlson July 28, 1914 2,340,117 Foster 1 Jan. 25, 1944 

